An illiterate deaf man who knows no sign language is being prosecuted in Pennsylvania. His linguistic deficit is either his biggest problem—particularly for participating in his defense—or the greatest loophole in his criminal career, depending who you ask.

Juan Jose Gonzalez Luna's defense lawyer believes his client was raised in an isolated town in the Mexican state of Michoacán. Luna met few (if any) other deaf people, and did not learn to read or write. He invents gestures and pantomimes to communicate. Though Luna is intellectually competent, his public defense lawyer has "a really hard time" communicating "even the most basic things. To try to describe legal procedure to someone like that is virtually impossible."

Nevertheless, he was arrested and charged for trafficking drugs. According to detectives who worked on the case, Luna's impenetrable silence is precisely what made him valuable to his King of Prussia-based gang:

Detectives arrested Gonzalez Oct. 8 after a purported cross-country smuggling drive, from Las Vegas to the Philadelphia suburbs, and seized more than two pounds of cocaine from his car.

"He makes the perfect drug mule," First Assistant District Attorney Kevin Steele said. "He can't consent to a search. He can't answer any questions about the operation."

Gonzalez has shown some limited ability to communicate.

Arriving at a recent preliminary hearing, he motioned toward detectives gathered around him. He pinched at his neck as if adjusting an invisible necktie. He bent his other arm mid-torso and clenched its fist, mimicking a heavy briefcase.

"He can't talk to the judge," one detective joked. "But of course he knows how to ask for his lawyer."

According to the Philadelphia Inquirer's fascinating article on the topic, similar cases have arisen from time to time in other states. A New Jersey man accused of raping two children was ordered to learn American Sign Language in a state hospital; in 18 years, he has never been deemed competent enough to stand trial. Other courts have developed laborious methods for "translating" into whatever ad hoc visual creole works for the particular defendant.